Manufacturers of consumer goods face enormous costs for goods damaged during shipping and handling. The consumer goods are frequently shipped in corrugated containers where the corrugation acts as a support for the load of other containers when stacked on top of each other. Clamp trucks are often used to move these corrugated containers around the warehouse and onto trucks that ship the goods. The clamp trucks have opposed solid plates that squeeze a load of corrugated containers with enough force to suspend the containers therebetween as the load is transported intact. The edges of the steel plates of the clamp trucks can crease the corrugated containers, reducing top load strength. This reduction in strength frequently causes the container to fail when top loaded, resulting in increased costs due to damaged goods.
Manufacturers can avoid the clamp truck problem by placing the load of corrugated containers upon wooden pallets and transferring them using fork trucks. The corrugated containers are initially stacked on captive pallets, a high quality pallet retained by the manufacturer for repeated use, for storage in the warehouse. Before shipping, the manufacturer will transfer the load from the captive pallet to a shipping pallet. The captive pallet can then be re-used by the manufacturer and the shipping pallet containing the load is placed on a truck for transport. Existing load transfer machines are often inefficient and can damage the load while transferring the load from pallet to pallet.
U.S. Pat. No. 3,123,232 issued to Postlewaite on Mar. 3, 1964, discloses a mechanism in which a load stacked upon a first pallet is securely held between a pair of opposing clamps and tilted over 90.degree. where the first pallet is removed and replaced with a second pallet. The second pallet and the load are then returned to an upright position. The method of the Postlewaite patent is unsuitable for many kinds of loads.
U.S. Pat. No. 3,645,409 issued to Sinclair on Feb. 29, 1972, discloses a load transfer and pallet stacker which is used to transfer a unit load from a pallet to the platens of a lift truck. Although the load may then be transferred to another pallet from the lift truck, the procedure is cumbersome and inefficient.
U.S. Pat. No. 3,269,565, issued to Kemp on Aug. 30, 1966, discloses an apparatus for transferring palletized loads by lifting the load off one pallet, removing the old pallet, and then placing a replacement pallet under the load and then lowering the load onto the replacement pallet. The Kemp patent is not practical for use if the pallets are not of a consistent structure, design and quality to enable the lift fingers to slide between the slots of the pallets. The load may be damaged if it is of such a nature that it can not withstand the resulting force placed upon it by the fingers.